Electronic warfare had great importance mainly in the Second World War. Radar was one of the greatest inventions in the area at that time, reinventing the way war was viewed until then. Nowadays, modern combat aircraft has sophisticated warfare systems. One of them is known as radar warning receiver (RWR), responsible for alerting pilots to possible radar detection and guiding the direction in which it is being radiated. Technological innovations allowed the interaction of the microwave and optoelectronics area, leading to an area known as microwave photonics (MWP). This article presents a photonic link to replace the copper cables used by RWR systems, applying photonic technology in order to improve performance and benefit from the intrinsic characteristics that optical fiber offers to the system, offering a totally passive remote system, in which only one phase modulator is connected to the RWR antenna. The results obtained for a totally photonic link by experiment were satisfactory. As expected, a gain above the unit was obtained. However, the observed noise figure was higher than expected, which ended up resulting in a lower signal noise ratio.

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An investigation of the optic spectral components beating at the photodetector to recover the RF signal at the output of a sub-octave microwave photonic link is presented, by a theoretical and experimental approach. It is demonstrated the best efficiency is achieved when the carrier to sideband ratio (CSR) is 0 dB at a low bias voltage condition on Mach-Zehnder (MZM) intensity modulator. A RF power link gain improvement of 9.7 dB is demonstrated for a same photodetector incident optic power, compared with a link operating at quadrature bias voltage condition on the MZM.

This article has proposed the concept of a decoy that could be used against anti-radiation missiles (ARMs). The bait signals are generated remotely and transmitted to the sacrificial antenna site over a fiber-optic network. This network has the possibility to support broadband radar signals in the range of a few GHz. This study postulated a distance of 1 km in relation to its park of antennas, distance that may be greater. This analog fiber link was designed for radar signal transmission in the frequency range of 0.3 to 3 GHz. The theoretical results were compared with the experimental ones, and it was observed that the behavior of the radar signal power gained in the studied range is straight. Thus, the signal does not present distortions. The system proposed in this study is promising as a distraction for ARMs.